1. Technical Field
Embodiments disclosed herein generally relate to systems and methods of producing C2+ hydrocarbons by way of liquid phase reactions and high shear effects. Other embodiments relate to conversion of reactants in a liquid medium to C2+ hydrocarbons, specifically alkanes, olefins, alcohols, aromatics, acids, and/or combinations thereof, by using high shear. Particular embodiments relate to a high shear process for improving conversion and reaction of CH4 to produce desired hydrocarbons.
2. Background
Various processes are known for the conversion of carbonaceous feedstock (e.g., coal, natural gas, etc.) to higher value liquid fuel or petrochemicals. Large quantities of methane, the main component of natural gas, are available in many areas of the world. Methane is an important building block in organic reactions used in industry as well as an important fuel and hydrogen source. The methane content of natural gas may vary within the range of from about 40 volume percent to about 95 volume percent. Other constituents of natural gas may include ethane, propane, butanes, pentane (and heavier hydrocarbons), hydrogen sulfide, carbon dioxide, helium and nitrogen.
Natural gas in liquid form has a density of 0.415 and a boiling point of minus 162° C. It is therefore not readily adaptable to transport as a liquid except for marine transport in very large tanks with a low surface to volume ratio. Large-scale use of natural gas often requires a sophisticated and extensive pipeline system. A significant portion of the known natural gas reserves is associated with remote fields, to which access is difficult. For many of these remote fields, pipelining to bring the gas to potential users is not economically feasible.
Economically transporting methane from remote areas by converting the gas to a liquid has long been sought in the industry. In addition, existing processes and production facilities for producing products from methane-based reactions are typically subject to various constraints, such as mass flow and product yield limitations and plant size and energy consumption requirements.
The effect of increasing carbon dioxide emission on global warming is also a major concern of scientists and governments due to its effect on the environment. The increased use of fossil fuels as a source of power and heat is thought by some to be a reason for the increase in carbon dioxide emissions. Oxidation of hydrocarbons is also common practice in chemical reactions such as the oxidation of ethylene. The products of combustion of hydrocarbons depend on the particular hydrocarbons but ultimately are carbon dioxide and water. Releasing large amounts of carbon dioxide into the atmosphere is hypothesized to have adverse effects, and there are efforts underway as a result, to reduce carbon dioxide emission overall.
Technologies to sequester carbon dioxide can consume large amounts of energy, derived in many cases from fossil fuels, which thus results in little or no net reduction in carbon dioxide. A net increase in carbon dioxide production is the result in some cases.
A process that allows the reuse of carbon dioxide to produce a valuable product such as fuel or chemical feedstock would be of great benefit in reducing the purported effects of carbon dioxide on global warming. It would be additionally beneficial to develop a process to convert carbon dioxide into a liquid fuel that can be transported and/or used as a feedstock for refinery or petrochemical processes.
Accordingly, in view of the art, there is a need for efficient and economical methods and systems for converting carbon-based components, such as carbon monoxide (CO) or carbon dioxide (CO2) and/or low molecular weight alkanes, particularly methane (i.e., CH4) to higher-value products. Such methods and systems should permit conversion of CO, CO2, and/or CH4, and provide increased selectivity and yield of high-value liquid and gas hydrocarbons (e.g., C2+). There is a need for methods and systems that allow economically favorable conditions of operating temperature, pressure, and/or reaction time, and a need in industry for improving production of liquid and gaseous hydrocarbons via reaction of CO, CO2, and CH4.
It has also been found that the use of the local reaction conditions obtainable under conditions of high fluid shear can be very effective with liquid and multiphase streams. The creation of zones of extreme temperatures and pressures may facilitate non-equilibrium reaction rates. Such local zones, with conditions far different from those of the bulk fluid(s) in a reaction system, could desirably be employed to achieve commercially significant production rates for processes that would otherwise be infeasible in conventional industrial processes. Thus, there is a need to provide systems and methods capable of providing favorable rates of reaction and high conversion based on non-equilibrium reaction conditions to produce high value liquid and multiphase products.